The present invention relates to semiconductor fabrication, and in particular to bond pads and methods for fabricating the same.
In creating integrated circuit (IC) devices, the technology of interconnecting devices and device features is of great importance. Bond pads are frequently used for this purpose, it is a requirement in creating integrated circuit devices that simple and reliable bond pads can be produced.
After the fabrication process of an integrated circuit device is completed, it is usually installed into a package to be utilized on a printed circuit board (PCB) as part of a larger circuit. In order for the inner leads of the package to make electrical contact with the bonding pads of the IC devices, a metal bond is formed at the bond pad of the IC device with a lead extending to the inner lead of the package lead frame.
During formation of a bond, bond pad lift off may occur. This problem may result when a large heavy bond pad (e.g., an aluminum interconnect) is placed on top of layers of the IC device which have not formed a strong. bond with the underlying layers. During formation of the aluminum interconnect, it is common to form an underlying barrier layer of a material, such as titanium nitride. This barrier layer is utilized to prevent aluminum from spiking into any underlying conductive layers during later fabrication steps. The barrier layer, however, which is usually titanium nitride, does not form a strong adhesion to the oxide underlying the bond pad and may separate during the bonding process.
Therefore, an improved bond pad, whereby a bond may be formed at a bond pad which is resistant to layer separation from adjacent layers, is desired.